A valve amplifier against a solid-state one. They are not really rivals: they differ in character, in what they will drive and in what owning them involves, so start there rather than with the watts.
| Area | Better | Why |
|---|
| Power | evenly matched | Effectively the same output - 75W against 70W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases modestly (110W and 100W). |
| Noise floor | B | Marantz Model 40n is the quieter design on paper - 106dB against 100dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Streaming | B | Only Marantz Model 40n has AirPlay 2, Roon and HEOS. |
| Room to grow | evenly matched | Only Advance Paris A8 APEX offers a pre-out/main-in loop; only Marantz Model 40n offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier type | depends | Advance Paris A8 APEX is Hybrid and Marantz Model 40n is Solid State. Valve designs are usually warmer and softer at the limits and need their tubes replaced eventually; solid state is the lower-maintenance choice. This is a taste and ownership decision, not a quality one. |
| Shelf space | depends | Advance Paris A8 APEX takes up about 22% less shelf area (1660cm² against 2126cm²), and it is 95mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Marantz Model 40n costs less - $2,499 against $2,999 at list. |
A Advance Paris A8 APEX B Marantz Model 40n
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both amplifiers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Marantz Model 40n is the easier recommendation: it leads on most of the measured areas and costs less. Take Advance Paris A8 APEX if one of the "depends" rows above describes your system.
What a spec sheet cannot show: how either sounds with your speakers, how the controls feel day to day, and what the app is like to live with - which is where most all-in-one amplifiers are actually won or lost. Power figures are the manufacturers' own and are not measured to a common standard, so treat small differences as noise. If you can hear both, that will tell you more than any row above.